How much land for veggies , goats, and chickens to feed ten families of five? I'm talkin southern OR

I'm working on a community project in southern Oregon, where we are building a farm/homeless shelter. We will teach subsistence farming, on a for profit subsidiary of our non-profit. The shelter is for families, and will house and feed three families for a year. I'm just trying get an Idea of how much land we'll need.